A novel liquid hybrid precursor method via sol-gel for the preparation of ZrB_2 films

摘要

Zirconium diboride (ZrB2) films were produced by liquid hybrid precursor method. Firstly, solutions of zirconium oxychloride octahydrate (ZrOCl2 center dot 8H(2)O), boric acid, sucrose and citric acid were mixed. Secondly, ammonium hydroxide was utilized to adjust pH and polyvinyl alcohol (PVA) acted as the aid of film formation. Next, through dip-coating and multi-step drying method, ZrB2 precursor films were fabricated. Finally, ZrB2 ceramic films were obtained via pyrolyzing the hybrid precursor at high temperature. The pyrolysis behaviors of the precursor were also investigated by XRD, SEM and pore-size distribution analysis. It was found that relatively stable structure was produced by sol-gel among the raw materials. The densification of ceramic films was reinforced as the pyrolysis temperature increased. As a result, the ZrB2 ceramic film obtained at 1600 degrees C exhibited integrated crystal structure and uniform morphology with pores diameter of 2-5 nm.